Fill level measurement devices and other measurement devices that are used for example in the field of monitoring objects are known and emit electromagnetic waves or ultrasound waves in the form of a transmission signal, which are reflected at least in part from the filling material surface or the corresponding object. The transmission signal (measurement signal) which is reflected at least in part can then be received by the antenna unit of the measurement device and analysed by the electronics connected thereto.
By scanning over the surface of the filling material or object, it is possible to determine the topology of the filling material surface or the object, respectively. In the field of fill level measurement, “topology” is understood to mean the shape of the surface of the filling material or bulk material. In this context, the term “topography” can also be used.
In order to supply the measurement devices with electrical energy and transmit the obtained data to an external device, the measurement devices can be equipped with what is referred to as a “four-wire interface”.